Topological stereochemistry. IX: Synthesis and cutting in half of a molecular Möbius strip

Topology has suggested several classic targets for chemical synthesis, including molecular Mobius strips. Details of the first synthesis of a molecular Mobius strip, possessing a three rung Mobius ladder molecular graph, are described. The structure is composed of crown ether rings fused by the tetrahydroxymethylethylene (THYME) unit-the rungs of the Mobius ladder are thus carbon-carbon double bonds and the single edge is a polyether chain of 60 atoms. A chemical realization of the classic topological trick of cutting a Mobius strip «in half» only to have it remain in one piece is accomplished by ozonolysis of the double bonds, and serves as an elegant corroboration of the topology of the structure. In addition, just as topology suggested targets for synthesis, the sy- nthesis has stimulated new topology